Everyone on board died in the bombing, alongside 11 people from Lockerbie in the worst ever terror attack on UK soil.

Gauci's evidence was later questioned amid allegations he was paid to testify and he was described as an "unreliable" witness by the Scottish Criminal Cases Review Commission.

He died of natural causes, according to reports.

George Thomson, who worked for Mr Al-Megrahi's defence team, told the Times of Malta: "I personally hope that Tony is in a better place and that he is now at peace because he must have led a tortured life knowing that he had jailed an innocent man for money."

Megrahi, who had terminal cancer, died in 2012 after being released from jail on compassionate grounds in 2009.